mirror of
https://github.com/ecency/ecency-mobile.git
synced 2024-12-21 12:21:31 +03:00
278 lines
8.4 KiB
C++
278 lines
8.4 KiB
C++
//-----------------------------------------------------------------------------
|
|
// boost variant/detail/visitation_impl.hpp header file
|
|
// See http://www.boost.org for updates, documentation, and revision history.
|
|
//-----------------------------------------------------------------------------
|
|
//
|
|
// Copyright (c) 2003
|
|
// Eric Friedman
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See
|
|
// accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
|
|
#ifndef BOOST_VARIANT_DETAIL_VISITATION_IMPL_HPP
|
|
#define BOOST_VARIANT_DETAIL_VISITATION_IMPL_HPP
|
|
|
|
#include <boost/config.hpp>
|
|
|
|
#include <boost/variant/detail/backup_holder.hpp>
|
|
#include <boost/variant/detail/cast_storage.hpp>
|
|
#include <boost/variant/detail/forced_return.hpp>
|
|
#include <boost/variant/detail/generic_result_type.hpp>
|
|
#include <boost/variant/variant_fwd.hpp> // for BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
|
|
|
|
#include <boost/mpl/eval_if.hpp>
|
|
#include <boost/mpl/bool.hpp>
|
|
#include <boost/mpl/identity.hpp>
|
|
#include <boost/mpl/int.hpp>
|
|
#include <boost/mpl/next.hpp>
|
|
#include <boost/mpl/deref.hpp>
|
|
#include <boost/mpl/or.hpp>
|
|
#include <boost/preprocessor/cat.hpp>
|
|
#include <boost/preprocessor/inc.hpp>
|
|
#include <boost/preprocessor/repeat.hpp>
|
|
#include <boost/type_traits/is_same.hpp>
|
|
#include <boost/type_traits/has_nothrow_copy.hpp>
|
|
#include <boost/type_traits/is_nothrow_move_constructible.hpp>
|
|
|
|
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
|
|
# pragma warning (push)
|
|
# pragma warning (disable : 4702) //unreachable code
|
|
#endif
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// BOOST_VARIANT_VISITATION_UNROLLING_LIMIT
|
|
//
|
|
// Unrolls variant's visitation mechanism to reduce template instantiation
|
|
// and potentially increase runtime performance. (TODO: Investigate further.)
|
|
//
|
|
#if !defined(BOOST_VARIANT_VISITATION_UNROLLING_LIMIT)
|
|
|
|
#ifndef BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES
|
|
# include <boost/mpl/limits/list.hpp>
|
|
# define BOOST_VARIANT_VISITATION_UNROLLING_LIMIT \
|
|
BOOST_MPL_LIMIT_LIST_SIZE
|
|
#else
|
|
# define BOOST_VARIANT_VISITATION_UNROLLING_LIMIT \
|
|
BOOST_VARIANT_LIMIT_TYPES
|
|
#endif
|
|
|
|
#endif
|
|
|
|
namespace boost {
|
|
namespace detail { namespace variant {
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// (detail) class apply_visitor_unrolled
|
|
//
|
|
// Tag type indicates when visitation_impl is unrolled.
|
|
//
|
|
struct apply_visitor_unrolled {};
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// (detail) class template visitation_impl_step
|
|
//
|
|
// "Never ending" iterator range facilitates visitation_impl unrolling.
|
|
//
|
|
|
|
|
|
template <typename Iter, typename LastIter>
|
|
struct visitation_impl_step
|
|
{
|
|
typedef typename mpl::deref<Iter>::type type;
|
|
|
|
typedef typename mpl::next<Iter>::type next_iter;
|
|
typedef visitation_impl_step<
|
|
next_iter, LastIter
|
|
> next;
|
|
};
|
|
|
|
template <typename LastIter>
|
|
struct visitation_impl_step< LastIter,LastIter >
|
|
{
|
|
typedef apply_visitor_unrolled type;
|
|
typedef visitation_impl_step next;
|
|
};
|
|
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// (detail) function template visitation_impl_invoke
|
|
//
|
|
// Invokes the given visitor on the specified type in the given storage.
|
|
//
|
|
|
|
template <typename Visitor, typename VoidPtrCV, typename T>
|
|
inline
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type)
|
|
visitation_impl_invoke_impl(
|
|
int, Visitor& visitor, VoidPtrCV storage, T*
|
|
, mpl::true_// never_uses_backup
|
|
)
|
|
{
|
|
return visitor.internal_visit(
|
|
cast_storage<T>(storage), 1L
|
|
);
|
|
}
|
|
|
|
template <typename Visitor, typename VoidPtrCV, typename T>
|
|
inline
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type)
|
|
visitation_impl_invoke_impl(
|
|
int internal_which, Visitor& visitor, VoidPtrCV storage, T*
|
|
, mpl::false_// never_uses_backup
|
|
)
|
|
{
|
|
if (internal_which >= 0)
|
|
{
|
|
return visitor.internal_visit(
|
|
cast_storage<T>(storage), 1L
|
|
);
|
|
}
|
|
else
|
|
{
|
|
return visitor.internal_visit(
|
|
cast_storage< backup_holder<T> >(storage), 1L
|
|
);
|
|
}
|
|
}
|
|
|
|
template <typename Visitor, typename VoidPtrCV, typename T, typename NoBackupFlag>
|
|
inline
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type)
|
|
visitation_impl_invoke(
|
|
int internal_which, Visitor& visitor, VoidPtrCV storage, T* t
|
|
, NoBackupFlag
|
|
, int
|
|
)
|
|
{
|
|
typedef typename mpl::or_<
|
|
NoBackupFlag
|
|
, is_nothrow_move_constructible<T>
|
|
, has_nothrow_copy<T>
|
|
>::type never_uses_backup;
|
|
|
|
return (visitation_impl_invoke_impl)(
|
|
internal_which, visitor, storage, t
|
|
, never_uses_backup()
|
|
);
|
|
}
|
|
|
|
template <typename Visitor, typename VoidPtrCV, typename NBF>
|
|
inline
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type)
|
|
visitation_impl_invoke(int, Visitor&, VoidPtrCV, apply_visitor_unrolled*, NBF, long)
|
|
{
|
|
// should never be here at runtime!
|
|
typedef typename Visitor::result_type result_type;
|
|
return ::boost::detail::variant::forced_return< result_type >();
|
|
}
|
|
|
|
///////////////////////////////////////////////////////////////////////////////
|
|
// (detail) function template visitation_impl
|
|
//
|
|
// Invokes the given visitor on the type in the given variant storage.
|
|
//
|
|
|
|
template <
|
|
typename W, typename S
|
|
, typename Visitor, typename VPCV
|
|
, typename NBF
|
|
>
|
|
inline
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type)
|
|
visitation_impl(
|
|
int, int, Visitor&, VPCV
|
|
, mpl::true_ // is_apply_visitor_unrolled
|
|
, NBF, W* = 0, S* = 0
|
|
)
|
|
{
|
|
// should never be here at runtime!
|
|
typedef typename Visitor::result_type result_type;
|
|
return ::boost::detail::variant::forced_return< result_type >();
|
|
}
|
|
|
|
template <
|
|
typename Which, typename step0
|
|
, typename Visitor, typename VoidPtrCV
|
|
, typename NoBackupFlag
|
|
>
|
|
inline
|
|
BOOST_VARIANT_AUX_GENERIC_RESULT_TYPE(typename Visitor::result_type)
|
|
visitation_impl(
|
|
const int internal_which, const int logical_which
|
|
, Visitor& visitor, VoidPtrCV storage
|
|
, mpl::false_ // is_apply_visitor_unrolled
|
|
, NoBackupFlag no_backup_flag
|
|
, Which* = 0, step0* = 0
|
|
)
|
|
{
|
|
// Typedef apply_visitor_unrolled steps and associated types...
|
|
# define BOOST_VARIANT_AUX_APPLY_VISITOR_STEP_TYPEDEF(z, N, _) \
|
|
typedef typename BOOST_PP_CAT(step,N)::type BOOST_PP_CAT(T,N); \
|
|
typedef typename BOOST_PP_CAT(step,N)::next \
|
|
BOOST_PP_CAT(step, BOOST_PP_INC(N)); \
|
|
/**/
|
|
|
|
BOOST_PP_REPEAT(
|
|
BOOST_VARIANT_VISITATION_UNROLLING_LIMIT
|
|
, BOOST_VARIANT_AUX_APPLY_VISITOR_STEP_TYPEDEF
|
|
, _
|
|
)
|
|
|
|
# undef BOOST_VARIANT_AUX_APPLY_VISITOR_STEP_TYPEDEF
|
|
|
|
// ...switch on the target which-index value...
|
|
switch (logical_which)
|
|
{
|
|
|
|
// ...applying the appropriate case:
|
|
# define BOOST_VARIANT_AUX_APPLY_VISITOR_STEP_CASE(z, N, _) \
|
|
case (Which::value + (N)): \
|
|
return (visitation_impl_invoke)( \
|
|
internal_which, visitor, storage \
|
|
, static_cast<BOOST_PP_CAT(T,N)*>(0) \
|
|
, no_backup_flag, 1L \
|
|
); \
|
|
/**/
|
|
|
|
BOOST_PP_REPEAT(
|
|
BOOST_VARIANT_VISITATION_UNROLLING_LIMIT
|
|
, BOOST_VARIANT_AUX_APPLY_VISITOR_STEP_CASE
|
|
, _
|
|
)
|
|
|
|
# undef BOOST_VARIANT_AUX_APPLY_VISITOR_STEP_CASE
|
|
|
|
default: break;
|
|
}
|
|
|
|
// If not handled in this iteration, continue unrolling:
|
|
typedef mpl::int_<
|
|
Which::value + (BOOST_VARIANT_VISITATION_UNROLLING_LIMIT)
|
|
> next_which;
|
|
|
|
typedef BOOST_PP_CAT(step, BOOST_VARIANT_VISITATION_UNROLLING_LIMIT)
|
|
next_step;
|
|
|
|
typedef typename next_step::type next_type;
|
|
typedef typename is_same< next_type,apply_visitor_unrolled >::type
|
|
is_apply_visitor_unrolled;
|
|
|
|
return detail::variant::visitation_impl(
|
|
internal_which, logical_which
|
|
, visitor, storage
|
|
, is_apply_visitor_unrolled()
|
|
, no_backup_flag
|
|
, static_cast<next_which*>(0), static_cast<next_step*>(0)
|
|
);
|
|
}
|
|
|
|
}} // namespace detail::variant
|
|
} // namespace boost
|
|
|
|
#if BOOST_WORKAROUND(BOOST_MSVC, >= 1400)
|
|
# pragma warning(pop)
|
|
#endif
|
|
|
|
#endif // BOOST_VARIANT_DETAIL_VISITATION_IMPL_HPP
|